<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<title>flex4</title>
<meta name="description" content="">
<meta name="keywords" content="">
<link href="./index.css" rel="stylesheet">
<style>
  body,html{
    height: 100%;
  }
</style>
</head>
<body>
  <div class="flex4">
    <header class="header"></header>
    <div class="main">
      <div class="flex4-left">
        <div style="width:100%;height:1000px;;">11212</div>
      </div>
      <div class="flex4-right">
        <div style="width:100%;height:1000px;;">121212</div>
      </div>
    </div>
    <footer class="footer"></footer>
  </div>
</body>
</html>